Annex D (normative) Compatibility features [depr]

D.6 char* streams [depr.str.strstreams]

D.6.3 Class ostrstream [depr.ostrstream]

D.6.3.1 ostrstream constructors [depr.ostrstream.cons]

ostrstream();
Effects: Constructs an object of class ostrstream, initializing the base class with ostream(&sb) and initializing sb with strstreambuf().
ostrstream(char* s, int n, ios_base::openmode mode = ios_base::out);
Effects: Constructs an object of class ostrstream, initializing the base class with ostream(&sb), and initializing sb with one of two constructors:
  • If (mode & app) == 0, then s shall designate the first element of an array of n elements.
    The constructor is strstreambuf(s, n, s).
  • If (mode & app) != 0, then s shall designate the first element of an array of n elements that contains an ntbs whose first element is designated by s.
    The constructor is strstreambuf(s, n, s + std​::​strlen(s)).333
The function signature strlen(const char*) is declared in <cstring> ([cstring.syn]).